Long-distance telephonic communications have become a necessity to the efficient operation if not the survival of innumerable corporate and governmental entities. Contemporaneously with the growth of this need has come a voluminous expansion in the abuse of such services by unauthorized individuals gaining access to a telephone instrument. Additionally, because of the great number of relatively low-cost individual toll calls now being made, it has become increasingly more difficult to economically recapture authorized total long-distance telephone operating costs, which even for many small and moderately sized entities frequently amount to thousands of dollars each month.
Electronic devices recently devised to provide such cost accounting generally have been placed in one of two categories: "active" or "passive". Active telephone management systems are those that automatically select the most inexpensive toll call routing from several available alternatives (e.g., wide area telephone service (WATS), leased line, foreign exchange, satellite channel, private carrier or regular network). Passive telephone management systems simply keep track of outgoing long-distance calls and periodically generate hard-copy reports of the same.
Heretofore only active telephone management systems, costing several tens of thousands of dollars, have been capable of limiting user access to the toll-call network. Because these systems select the least costly toll call routing at the time of each call, they do not also provide logging features. On the other hand, if one is desirous of charging the actual user or called party for toll call expenses, the hard-copy logging reports furnished by passive telephone management systems require enormous manual labor investments to first correlate each call with its actual cost as provided upon telephone company statements. Existing passive telephone management systems also require large blocks of costly integrated circuit memory that are subject to loss of data in the event of power interruptions.